Sanitary napkin having barrier means

ABSTRACT

A sanitary napkin (210) is provided with a barrier means (107) to provide a barrier against lateral migration of body fluids. The barrier means (107) can be provided on a sanitary napkin (210) which has no wings and comprises in this core a distal edge (278, 278&#39;) which is located within the perimeter of the absorbent core (212) during use of the sanitary napkin. The barrier means (107) can also be provided on a sanitary napkin (210) having wings (224, 224&#39;) and can be formed of a unitary part of the napkin&#39;s topsheet (214) or can be formed by a separate strip of material.

FIELD OF THE INVENTION

The invention relates to a sanitary napkin comprising

an absorbent core having a first face, a second face, a perimetercomprising two longitudinal sides and two lateral sides,

a liquid-pervious topsheet overlaying the first face of the core,

a liquid-impervious backsheet associated with the topsheet, thebacksheet overlying the second face of the core, and

barrier means located along the longitudinal sides for restrictingliquid migration in a direction generally parallel to the lateral sides.

BACKGROUND OF THE INVENTION

Such a sanitary napkin is known from the British patent application GB 2168 253.

In this patent application, the barrier means are located outside theperimeter of the core and are formed by an elasticised upstanding partof the topsheet and the backsheet. While lateral liquid migration isreduced by the barrier means, the rate of absorption of liquid entrappedbetween the barrier means and the core may be reduced. The knownsanitary napkin may also undergo a shift in position during use.

It is an object of the invention to provide for barrier means in asanitary napkin which are comfortable during use, which effectivelyrestrict lateral spread of body fluids and which allow adequateabsorption.

It is another object of the invention to provide a sanitary napkin whichcan be reliably positioned with respect to a user's undergarment.

SUMMARY OF THE INVENTION

A sanitary napkin according to the invention is characterized in thatthe barrier means comprise a wall having a free edge which is elevatedabove the plane of the first face of the core, the free edge being, atleast during use of the sanitary napkin, located within the perimeter ofthe core.

By placing the barrier means so that at least the free edge is duringuse located on top of the absorbent core, instead of beside it, theliquid that is stopped by the barrier means from laterally spreadingalong the topsheet, is readily absorbed by the core.

Another absorbent article according to the invention is characterized inthat the backsheet extends beyond the perimeter of the core to formflaps for attachment to a garment during use, the barrier meanscomprising a wall that is connected to the flaps adjacent the perimeterof the core.

The flaps can fold upward around the edge of an undergarment of thewearer, as is disclosed in U.S. Pat. No. 4,687,478 which is herebyincorporated by reference. It was found, that the flaps in combinationwith the barrier means provide for reduced lateral migration of bodyfluids. The barrier means can be formed by a liquid-impermeable wall orby an absorbent strip which is connected, for instance by gluing or byfusion bonding, to the flaps. The free edge of the wall is preferablylocated within the perimeter of the core during use of the sanitarynapkin for effective absorption of the body fluids that are retained bythe wall. It is however also possible that the fee edge of the wall islocated outside the perimeter of the core, or, for instance when ashaped core is used, is located within the perimeter of the core for thebroader parts of the core only.

An embodiment of an absorbent article according to the invention ischaracterized in that the wall is formed by a spacing member locatedbetween the topsheet and the backsheet.

The spacing member can be formed by a cantilever of flexible materialthat is placed between the topsheet and the backsheet outside theperimeter of the core and that presses the topsheet upwards. During useof the sanitary napkin, the napkin is compressed in a direction of thelateral sides and the topsheet is lifted by the cantilever. Preferablythe free edge of the wall that is formed by the topsheet and thecantilever is pressed within the perimeter of the core during use of thesanitary napkin, to provide a good absorption of body fluids retained bythe cantilever.

The barrier means can also comprise a foam strip which is glued, orotherwise connected, between the topsheet and the core or which is gluedon top of the topsheet.

Another embodiment of an absorbent article according to the invention ischaracterized in that the barrier means comprises the topsheet, thetopsheet having a central part overlaying the core and marginal partsforming the wall along the longitudinal sides of the core.

Even though the topsheet is fluid-pervious, the barrier means causerestriction of lateral spread of body fluids. Use of the topsheet toform the wall reduces the need for a separate barrier means and hencekeeps the number of components used in the sanitary napkin low, which isdesirable during manufacturing. The barrier means can extend along thewhole of the perimeter of the core to also prevent fluid migration in ageneral direction of the longitudinal sides.

Preferably the free edge of the barrier means is contracted before use,so that during use the barrier means is stretched and is pulled awayfrom the topsheet to stand up. The contraction can be caused by theapplication of an elastic member in its pre-stretched state along thefree edge of the barrier means. The free edge of the barrier means,which can be formed by either the topsheet, the backsheet or thecombination thereof, can also be crimped by application of heat toshorten the free edge of the barrier means. Shortening of the free edgein this way will also make the barrier means stand up uponlongitudinally stretching the sanitary napkin during use.

BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments of a sanitary napkin according to the invention will bedescribed in detail with reference to the accompanying drawings. In thedrawings:

FIG. 1 is a plan view of a sanitary napkin of the present invention,

FIG. 2 is a cross sectional view of the sanitary napkin of FIG. 1 alongthe line 2--2 of FIG. 1, the barrier means being formed by the topsheet,

FIG. 3 is a cross sectional view of a sanitary napkin according to theinvention, the barrier means being formed by the topsheet and locatedwithin the perimeter of the core,

FIG. 4 is a cross-sectional view of an embodiment of a sanitary napkinaccording to the invention, the barrier means being formed by thebacksheet,

FIG. 5 is a cross-sectional view of an embodiment of a sanitary napkin,the barrier means being formed by a foam strip,

FIG. 6 is an embodiment of a sanitary napkin, the barrier means beingformed by a cantilever,

FIG. 7 is an embodiment of a sanitary napkin having flaps, the barriermeans being formed by a strip which is glued to the flaps,

FIG. 8 is a front view of a conventional panty in which a sanitarynapkin according to the invention can be used,

FIG. 9 is a cross sectional view of the panty of FIG. 8 taken along line6--6 showing the sanitary napkin of FIG. 1 disposed therein and

FIG. 10 is a fragmentary coronal view showing the sectioned sanitarynapkin and panty of FIG. 8 in place on a user.

DETAILED DESCRIPTION OF THE INVENTION

A preferred embodiment of a sanitary napkin of the present invention isshown in FIGS. 1 and 2. Sanitary napkin 210 comprises an absorbent meansrepresented by central absorbent pad 212 and two flaps 224 and 224'. (Inthe discussion that follows, unless otherwise noted, the sanitarynapkins will have two flaps. While it is not necessary that the flaps beidentical, or, more properly, mirror images one of the other, theypreferably are. Thus the description of the first will be a descriptionof the second. Discussion of the second will, therefore, be omitted forclarity of exposition. Corresponding elements are indicated in thedrawings by reference numerals and primed reference numerals).

Flap 224 is associated with central absorbent pad 212 along nonlinearline of juncture 226. As used in the context of the presentspecification, the term "nonlinear" refers to any of various curved, asopposed to straight, lines.

Flap 224 has distal edge 278 which is remote from line of juncture 226.In the embodiment illustrated in FIG. 1, line of juncture 226 is concaverelative to distal edge 278. That is to say, line of juncture 226 curvesaway from distal edge 278. In this embodiment, nonlinear lines ofjuncture 226 and 226' and seam 239 define an absorbent means (centralabsorbent pad 212) which is narrower in its central region that at itsends. A sanitary napkin narrower in the center than at the ends isgenerally perceived by the user as more comfortable than a sanitarynapkin of uniform width.

Flap 224 is provided with first imaginary axis of flexibility 256 andsecond axis of flexibility 234.

FIG. 2, a cross sectional view of sanitary napkin 210 taken along line2--2, illustrates generally the preferred construction for sanitarynapkin 210. As shown in FIG. 2, central absorbent pad 212 comprisesabsorbent core 216. Central absorbent pad 212 and flap 224 both comprisetopsheet 214. Backsheet 218 is disposed on the side of absorbent core216 and flap 224 opposite that of topsheet 214. In effect, topsheet 214forms one surface of flap 224 while backsheet 218 forms the othersurface; topsheet 214 also forms one surface of central absorbent pad212, backsheet 218 the other.

In the embodiment illustrated, flap absorbent core 230 is interposedbetween topsheet 214 and backsheet 218. For simplicity of construction,flap absorbent core 230 extends throughout napkin 210 and is interposedbetween absorbent core 216 and backsheet 218. While this is a preferredembodiment primarily for reasons of construction, it is not necessarythat flap absorbent core 230 be interposed between absorbent core 216and backsheet 218.

Topsheet 214 and backsheet 218 are joined at seam 239 around the entireperiphery of sanitary napkin 210. The purpose of this seam is to unitethe various elements of the sanitary napkin into a whole. Topsheet 214is secured to flap absorbent core 230 and backsheet 218 along nonlinearlines of juncture 226 and 226' by attachment means not illustrated inFIG. 2.

Illustrated in FIG. 2 are the adhesive attachment means central padadhesive 220 and flap adhesive 236 which are covered by, respectively,central pad release liner 222 and flap release liner 238. These adhesiveattachment means are adapted to secure sanitary napkin 210 within thecrotch region of an undergarment.

Topsheet 214 is liquid permeable and, when sanitary napkin 210 is inuse, is in close proximity to the skin of the user. Topsheet 214 iscompliant, soft feeling and non-irritating to the user's skin. It can bemade from any of the materials conventional for this type of use.Non-limiting examples of suitable materials that can be used as topsheet214 are woven and nonwoven polyester, polypropylene, nylon, and rayonand formed thermoplastic films; formed films are preferred. Suitableformed films are described un U.S. Pat. No. 4,324,246 issued to Mullaneand Smith on Apr. 13, 1982 and U.S. Pat. No. 4,342,314 issued to Radeland Thompson on Aug. 3, 1982, both of which patents are incorporatedherein by reference. Formed films are preferred for topsheet 214 becausethey are pervious to liquids and yet non-absorbent. Thus, the surface ofthe formed film, which is in contact with the body, remains dry and ismore comfortable to the wearer.

In preferred embodiments of the present invention, the outer surface oftopsheet 214 is treated with a surfactant. Treating the outer surface ofthe topsheet with surfactant renders the surface more hydrophilic whichresults in liquid penetrating the topsheet faster than if the surfacewere not treated. This diminishes the likelihood that menstrual fluidwill flow off topsheet 214 rather than being absorbed by the absorbentcore 216. It is preferred that the surfactant be substantially evenlyand completely distributed across the outer surface of topsheet 214.This can be accomplished by any of the common techniques well known tothose skilled in the art. For example, the surfactant can be applied totopsheet 214 by spraying, by padding, or by the use of transfer rolls.

In preferred embodiments, the inner surface of topsheet 214 is securedin contacting relating to absorbent core 216. This contactingrelationship results in liquid penetrating topsheet 214 faster than ifit were not in contact with absorbent core 216. Topsheet 214 can bemaintained in contact with absorbent core 216 by applying adhesive,preferably in spaced, limited areas, to the inner surface of thetopsheet 214. Examples of suitable adhesives used for this purposeinclude the acrylic emulsion E1833BT manufactured by Rohm and HaasCompany of Philadelphia, Pa. and the acrylic emulsion WB3805manufactured by H. B. Fuller Company of St. Paul, Minn. The adhesivescan be applied by the same methods as the surfactant is applied to theouter surface of topsheet 214.

Referring to FIG. 2, it can be seen that absorbent core 216 ispositioned between topsheet 214 and backsheet 218. Absorbent core 216provides the means for absorbing menstrual fluid. Absorbent core 216 isgenerally compressible, conformable, and non-irritating to the user'sskin. It can comprise any material used in the art for such purpose.Examples of suitable materials are layers of tissue (such as wadding)and fibrated comminution pulp (airfelt), with fibrated comminution pulpbeing preferred.

Backsheet 218 is impervious to liquids and, thus, prevents menstrualfluid which may be expressed from absorbent core 216 from soiling theclothing of the user. Any material used in the art for such purpose canbe utilized herein. Suitable materials are embossed or nonembossedpolyethylene films and laminated tissue.

The outer surface of backsheet 218, generally in register with absorbentcore 216, is coated with central pad adhesive 220. Central pad adhesive220 provides an adhesive attachment means for securing central absorbentpad 212 in the crotch portion of a panty. Any adhesive or glue used inthe art for such purpose can be used herein, with pressure sensitiveadhesives being preferred. Suitable adhesives are Century A-305-IVmanufactured by the Century Adhesives Corporation and Instant Lok 342823manufactured by National Starch Company. As shown in FIG. 2, central padadhesive 220 is generally the same width as absorbent core 216; thewidth is not critical and appropriate widths, as well as lengths, can bereadily selected by those skilled in the art. The pressure sensitiveadhesive of central pad adhesive 220 should be covered with central padrelease liner 222 to keep the adhesive from drying out and to keep itfrom sticking to extraneous surfaces prior to use. Any commerciallyavailable release liner commonly used for such purposes can be usedherein. Nonlimiting examples of suitable release liners are BL 30 MG-ASilox E1/0 and BL 30 MG-A Silox 4 P/O both of which are manufactured bythe Akrosil Corporation.

As can be observed from the foregoing discussion, central absorbent pad212 is an absorbent means that has a fluid pervious body contactingsurface (represented in FIG. 2 by topsheet 214) and an opposed liquidimpervious surface (represented bin FIG. 2 by backsheet 218). It is tobe understood that the embodiment illustrated in only one possibleembodiment, albeit a preferred one. Other possible embodiments includeone in which an absorbent core is essentially completely wrapped withtopsheet before it is placed on a backsheet. The absorbent means canalso comprise an absorbent core which possesses sufficient integrity tostand alone and which is fluid permeable on one surface while the othersurface has been treated to render it liquid impervious.

It should be noted that a narrow central absorbent pad 212 is effectivebecause the overall configuration and use of sanitary napkin 210 resultsin central absorbent pad 212 being maintained in close proximity to thebody. Such proximity of central absorbent pad 212 places it preciselywhere it should: very near the body at the vaginal opening. Centralabsorbent pad 212 can then absorb the vast majority of the menstrualfluid (menses) before it has an opportunity to flow along centralabsorbent pad 212.

It is to be observed that lines of juncture 226 and 226' are the linesalong which flaps 224 and 224' are associated with the absorbent means(represented by central absorbent pad 212); as such they represent linesof demarcation between the absorbent means and the flaps. It is also tobe observed that the lines of juncture are nonlinear in this embodiment,but can also be straight. Preferably, they are concave relative todistal edges 278 and 278' and relative to the bulk of central absorbentpad 212. The absorbent means thus takes on a shape in which the width atits center is less than the width at its ends. This contoured shape isclosely attuned to anatomical dimensions of the crotch region of theuser. It makes the sanitary napkin more comfortable to wear while, atthe same time, making it more effective as by rendering it less subjectto compression by the legs of the user. While nonlinear lines ofjuncture which are convex relative to the distal edges and to the bulkof the central absorbent pad can be used, they are not preferred.

It is preferred that the width of central absorbent pad 212 betweenlines of juncture 226 and 226' at their nearest approach be from about 1to about 8 centimeters. The width of the central absorbent pad 212 atits ends should be from about 2 to about 9 centimeters. Centralabsorbent pad 212 should be from about 7.6 to about 38 centimeters long.

Central absorbent pad 212 need not have an absorbent capacity muchgreater than the total amount of menstrual fluid anticipated to beabsorbed. Thus, central absorbent pad 212, in addition to being narrow,can be relatively thin. Furthermore, a narrow and thin absorbent meansis extremely comfortable to the user. In the embodiment illustrated inFIGS. 1 and 2, topsheet 214 does not serve as a topsheet for flaps 224and 224'. In general, the flaps do not require a topsheet to enable themto function properly, but the use of a topsheet is preferred. Flaptopsheets can be integral with the absorbent means' body contactingsurface or they can be independent elements as illustrated; the formeris preferred. All the specific physical property comments made aboveabout topsheet 214 apply to any flap topsheet that is used. There is,however, no requirement that the flap topsheet be the same material asthe topsheet associated with the central absorbent pad. In preferredembodiments, the flap topsheet can be a nonwoven material while thetopsheet with the central absorbent pad is a formed film.

In the embodiment illustrated in FIGS. 1 and 2, backsheet 218 serves asa backsheet for flaps 224 and 224'. The flaps require a backsheet (ormore generally, a liquid impervious material) to enable them to functionproperly. The flap backsheets can be integral with the absorbent meansliquid impervious surface, as illustrated, or they can be independentelement; the former is preferred. All the specific physical propertycomments made above about backsheet 218 apply to any flap backsheet.

The overall size of flap 224 can be readily selected by those skilled inthe art. Preferably, sanitary napkin 210 is from about 10 to about 23centimeters wide between distal edges 278 and 278' at their greatestseparation. Preferably flap 224 is from about 7.6 to about 18centimeters long in the direction parallel to the longitudinal axis ofthe sanitary napkin.

The outer surface of flap 224, adjacent distal edge 278, is coated withflap adhesive 236.

Flap adhesive 236 is an adhesive attachment means which is used toassist in maintaining flap 234 in position after it is wrapped aroundthe edge of the crotch portion of a panty as described below. Anyadhesive used for central pad adhesive 220 can be used as flap adhesive236. Also, flap adhesive 236 is covered with a removable flap releaseliner 238. Any release liner material used for central pad release liner222 can be used for flap release liner 238.

As shown in FIGS. 1 and 2, topsheet 214 is secured to backsheet 218along seam 239. Seam 239 can be formed by any means commonly used in theart for this purpose such as by gluing, crimping or heat sealing. Seam239 is illustrated extending completely around the periphery of sanitarynapkin 210; this is a preferred embodiment for ease of construction.(Other means of uniting the various elements of the device can be used).

Topsheet 214 can be secured to backsheet 218 along lines of juncture 226and 226' by any of the techniques used to form seam 239.

Flap 224 contains first axis of flexibility 256 and second axis offlexibility 234. These two axes of flexibility allow flap 224 to form awall, in use, as described hereinafter. The axis of flexibility can beformed by a separate hinge line or can be located along a continuousrange in the flap 224, which is as flexible so as to bend around anydesired line.

First axis of flexibility 256 is so constructed as to allow the flap tobend along first axis of flexibility 256. The direction of the bend ofthe flap is upward when sanitary napkin 210 is in the configuration ofFIG. 2. More generally, the direction of the bend is such that thatportion of flap 224 containing distal edge 278 rotates about the firstaxis of flexibility 256 in an arc beginning generally from its extendedposition, as shown in FIG. 2, toward the fluid pervious body contactingsurface of the absorbent means (as represented in FIG. 2 by that portionof topsheet 214 in register with absorbent core 216) and away from theliquid impervious surface of the absorbent means (as represented in FIG.2 by that portion of backsheet 218 in register with absorbent core 216).

Second axis of flexibility 234 is so constructed as to allow the flap tobend along second axis of flexibility 234. The direction of the bend isdownward when sanitary napkin 210 is in the configuration of FIG. 2.More generally, the direction of the bend is such that that portion ofthe flap 224 containing distal edge 278 rotates about second axis offlexibility 234 in an arc generally from its extended position, as shownin FIG. 2, toward the liquid impervious surface of the absorbent means(as represented in FIG. 2 by that portion of backsheet 218 in registerwith absorbent core 216 as comprising central absorbent pad 212) andaway from the fluid pervious body contacting surface of the absorbentmeans (as represented in FIG. 2 by that portion of topsheet 214 inregister with absorbent core 216).

First and second axes of flexibility can be provided in various ways. Apreferred method is shown in FIGS. 1 and 2. In the embodimentillustrated, the materials of construction of flap 224 are selected sothat flap 224 is extremely flexible over essentially the whole of itsextent. Axes of flexibility of 256 and 234, as shown in FIGS. 1 and 2,are not, then, single, unique structures, but are, rather,representative of an essentially infinite number of pairs of axes. Thisarrangement is particularly preferred because it allows sanitary napkin210 to be easily adjusted, during application, to properly fit a numberof differently sized undergarments and, in use, anatomies of describedbelow.

Total flexibility of flap 224 permits flap 224 to be positioned aroundthe edge of the crotch portion of a panty without having to alter thenatural path of the edge of the crotch portion of a panty. thus, theedge of the crotch portion of a panty need not be stretched to fit tothe second flexible axis of the flap. Furthermore, the natural path ofthe edge of the crotch portion of a panty results, when the sanitarynapkin is in place for use, in the highest wall (described below) beingformed; this, in turn, provides the greatest barrier to flow of themenstrual fluid.

In the embodiment of sanitary napkin 210 illustrated in FIGS. 1 and 2,it is preferred that the materials of construction of flap 224 beselected so that the flap has a resistance to bending, through an arc of90° C., of less than about 200 grams, more preferably less than about 50grams, and most preferably less than about 25 grams as measured by thePCA Score Bend Tester manufactured by the Thwing-Albert InstrumentCompany of Philadelphia, Pa. These values are obtained when a section offlap 7.6 centimeters long (and which is maintained 2.5 centimeters abovethe bottom edge of the tilting plate of the tester) is evaluated underTAPPI standard conditions.

In the abstract, an axis is generally considered to be a linear element.The present axes of flexibility are also generally linear, but, sincethe materials from which the flaps are constructed generally possesssuch a degree of flexibility that the flaps can be bent and foldedconveniently with manual force, the axes of flexibility can becomenonlinear under the influence of external forces.

As illustrated in FIG. 1, first axis of flexibility 256 is in closeproximity to line of juncture 226. First axis of flexibility 256 can, infact, intersect the line of juncture 226 at the point the lattercontacts the outer margin of the sanitary napkin (as that margin isrepresented by seam 239). In the general case, this will be the onlysituation in which first axis of flexibility 256 and line of juncture226 touch or coincide. It is to be understood, however, that applicationof external forces during use can cause the first axis of flexibility tobe displaced toward the line of juncture so that, in some instances, thetwo can touch or coincide.

Sanitary napkins including the central absorbent pad comprising a liquidpervious topsheet, a liquid impervious backsheet, and an absorbent coreinterposed between the topsheet and the backsheet, and having a flapextending from each longitudinal edge of the central absorbent pad,wherein the line of juncture between each flap and the longitudinal edgeof the central absorbent pad is linear, and having each flap providedwith a flexible axis located in the body of the flap, can be constructedso that the sanitary napkin preferentially bends at the linear line ofjuncture of each flap and the longitudinal edge of the central absorbentpad as well as at the flexible axis located within the body of the flap.Such napkins, while distinctly different from those of the presentinvention, will function in a manner analogous to those of the presentinvention.

The precise shape of flap 224, as well as the overall shape of sanitarynapkin 210, can be selected by those skilled in the art without undueexperimentation. In the embodiments illustrated in FIGS. 1 and 3, theflaps are symmetrically disposed along the longitudinal axis of thesanitary napkin; while this is a preferred embodiment, it is not amandatory design feature. As noted above, the flaps are generally mirrorimages one of the other; while such a situation is preferred, it islikewise not a mandatory design condition.

Further, the sanitary napkins illustrated in FIGS. 1 and 2 areembodiments wherein the flaps are formed integrally with the topsheetsand backsheets of the sanitary napkin. Once again, while this is apreferred method of construction, it is not mandatory. Flaps and centralabsorbent means can be formed independently and joined by techniqueswell known to those skilled in the art in such a manner that theresulting sanitary napkin will function essentially equivalently to theembodiments illustrated herein.

In use, the sanitary napkins of this invention can be held in place byany support means well known for such purpose. Belts worn about thewaist of the user can be used. It is highly preferred, however, thatthey be placed in the user's panty undergarment as described below.

FIG. 8 is an undergarment of the type commonly worn by many women andwell known as a panty. It comprises front section 240, back section 242,and crotch portion 244 which joins front and back sections 240 and 242.Crotch portion 244 comprises two side edges 246 and 246' and centercrotch portion 248.

A sanitary napkin of the present invention, such as the one illustratedat 210 in FIGS. 1 and 2, is utilized by removing the release liners 222,238 and 238' and thereafter placing the sanitary napkin in a panty asshown in FIG. 9. The center of central absorbent pad 212 is placed incrotch portion 244 of the panty with one end of central absorbent pad212 extending toward front section 240 and the other end toward backsection 242 of the panty and with backsheet 218 in contact with theinner surface of center crotch portion 248 of the panty. Central padadhesive 220 maintains central absorbent pad 212 in position. The distalportions of flaps 224 and 224' are folded around, respectively, sideedges 246 and 246' of the panty by bending along second flexible axes234 and 234'. Flap adhesive 236 and 236' secure flaps 224 and 224' insuch position. Thus, flaps 224 and 224' are each folded over themselveswith a portion of the panty--including side edges 246 and246'--interposed therebetween.

Numerous benefits are derived from the use of the sanitary napkin of thepresent invention. Flaps 224 and 224' are wrapped around each edge 246and 246' of the crotch portion 244 of the panty as shown in FIG. 8. Thisencapsulation of the panty crotch assists in preventing the menstrualfluid from coming into contact with the center crotch portion of thepanty. Thus, the center crotch portion of the panty will not be soiled.

There are two other benefits. One is that the portions of the flapscontaining the second axes of flexibility, 234 and 234', provide anexcellent gasket-like seal against the body. The other is that thecentral absorbent means, such as central absorbent pad 212, ismaintained in excellent contiguous relationship to the body.

The edge of the crotch portion of a panty generally contains an elasticmaterial. When a panty is worn, the elastic of the edge of the crotchportion generates an upward force, i.e. against the body, due to theenergy in the elastic and the fit of the panty. The placement of thesecond axis of flexibility, such as second axes of flexibility 234 and234', between the body and the edges of the crotch portion of the pantyresults in the upward force generated by the edge of the crotch portionof the panty pushing the portion of the flaps containing the second axesof flexibility snugly against the body. This results in agasket-like-seal being formed along the axes of flexibility between theflaps and the body. This is illustrated in FIG. 10 which is afragmentary coronal view showing the sectioned sanitary napkin and pantyof FIG. 8 in place on a user. (A coronal view is the frontal plane thatpasses through the long axis of the body). The gasket-like seal assistsin preventing menstrual fluid from penetrating beyond the second axis offlexibility which, in turn, minimizes soiling of the legs and adjoiningclothing. Another benefit derived from the flaps being pushed snuglyagainst the body along the second axes of flexibility is that theabsorbent means (central absorbent pad) is forced into close proximityto and into conformity with the body. This, too, is illustrated in FIG.10. The maintenance of the central absorbent pad against the body isknown as "good body contact". Good body contact is beneficial because itprovides a barrier to lateral flow of menstrual fluid. Without such abarrier, menstrual fluid would tend to flow quickly along the topsheet,thereby providing less time for it to be absorbed by the absorbent core.

Inherent bunching is the formation of wrinkles along the lateral axes ofa sanitary napkin resulting from the initial placement of the sanitarynapkin in a panty for use. (Lateral axes of a sanitary napkin extendacross the "crotch portion" of the napkin generally parallel to line2--2 of FIG. 1). This inherent bunching is due to the facts that asanitary napkin is essentially linear along its longitudinal axis andthat the anatomical contour of the body where the sanitary napkin isplaced in essentially "U" shaped. (The longitudinal axis of a sanitarynapkin extends from end to end of the central absorbent means and isgenerally perpendicular to line 2--2 of FIG. 1). Thus, as soon as asanitary napkin is put in place, its shape is changed along itslongitudinal axis from being essentially linear to "U" shaped. Thischange in shape creates wrinkles along the lateral axes of the sanitarynapkin, with the vast majority of the wrinkles being at the point ofgreatest curvature of the body, i.e. the crotch area.

Forced bunching is the wrinkling of a sanitary napkin, along either itslateral or longitudinal axes, caused by movement of the legs of theuser.

Wrinkles in a sanitary napkin created by inherent and forced bunchingare known as flow channels because menstrual fluid can easily flow alongthe trough of the wrinkle in the absence of significant body contactalong the wrinkle.

The sanitary napkin of the present invention provides numerous benefitsbecause the flaps bend at the first axis of flexibility. In particular,the benefits provided are that:

(1) inherent bunching results in flow channels being formedsubstantially only in the central absorbent pad, not the bulk of theflaps;

(2) the sanitary napkin of the present invention can withstand muchforced bunching before flow channels are created;

(3) even if the forced bunching is harsh enough to create flow channels,the channels formed will be essentially limited to the central absorbentpad; and

(4) even if the forced bunching is so great that flow channels arecreated in both the central absorbent pad and the flaps, the menstrualfluid is restrained from penetrating beyond the second flexible axes ofthe flaps.

These four benefits are obtained because the sanitary napkin of thepresent invention is provided with barrier means or walls 107 andbecause it bends along the axes of flexibility. The anatomical featuresof the crotch area of a woman are such that the crotch section issubstantially trapezoidal shaped, with the center area of the crotch,which is located at the vaginal opening, being the base of thetrapezoid. When a sanitary napkin of the present invention, such as theembodiment shown in FIGS. 1 and 2, is in use, the anatomical features ofthe crotch area force the sanitary napkin to bend upward at the firstaxis of flexibility. This results in the sanitary napkin forming a wallat each side of the central absorbent pad; the wall extends from thefirst axis of flexibility to the second axis of flexibility, asillustrated in FIG. 10. Thus, in use, the sanitary napkin of the presentinvention has a well-like shape with the plane formed by the second axesof flexibility (234 and 234') that are wrapped around the edge of thecrotch portion of the panty (246 and 246') being higher than the planeformed by the first axes of flexibility (256 and 256') when the user isin an upright position.

Inherent bunching in the sanitary napkin of the present invention issubstantially limited to the central absorbent pad; essentially no flowchannels are formed in the walls. Without being bound by any theory, itis believed that when the flow channels are being formed, the energycreating them is transmitted across the central absorbent pad and theflow channels are extended. This proceeds until the flow channels reachthe first axes of flexibility. The flow channels extend no farther thanthis because, it is believed, the first axes of flexibility relieve theenergy extending the flow channels. Thus the flow channels will notreach the gasket-like seal formed between the flap and the body at thesecond axis of flexibility, and, therefore, the seal will remain intact.The gasket-like seal forms a dam and blocks the flow of the menstrualfluid. The menstrual fluid can then be absorbed (or absorbed) by theabsorbent core.

The sanitary napkin of the present invention can withstand much forcedbunching before any flow channels are created, because the energytransmitted to the sanitary napkin by the forced bunching results in thewalls tending to rotate around each first axis of flexibility. Withoutsuch rotation flow channels would be formed.

Even if the forced bunching is harsh enough to create flow channels, thechannels will be substantially limited to the central absorbent pad.This is true for the same reasons that inherent bunching forms flowchannels only in the central absorbent pad. Therefore, the gasket-likeseal will remain intact and form a dam and block the flow of themenstrual fluid until it can be absorbed by the absorbent core.

Even if the forced bunching is so great that flow channels are createdin both the central absorbent pad and the flaps, menstrual fluid isrestrained from penetrating beyond the walls 107 and beyond the secondaxes of flexibility of the flaps. Such flow channels are likely to breakthe gasket-like seal. However, menstrual fluid is restrained frompenetrating beyond the second flexible axes of the flaps because thewalls themselves will form a barrier to flow of menstrual fluid.Menstrual fluid would have to flow up the walls, which is substantiallydirectly against the force of gravity when the user is in an uprightposition, in order to penetrate the break in the gasket-like seal. Thusthe walls themselves restrain the flow of the menstrual fluid.

In summary, the sanitary napkin of the present invention forms flowchannels essentially only in the central absorbent pad which results inthe gasket-like seal remaining intact. Thus, menstrual fluid will notflow beyond the gasket-like seal. However, if the forced bunching is sogreat that the gasket-like seal breaks, the walls themselves restrainthe flow of the menstrual fluid.

It is important to note that in FIG. 10 flap adhesive 236 is illustratedas contacting the edge of the panty only on its "outer" surface. Whilethis is a preferred way of securing the sanitary napkin in the panty,flap adhesive can contact the edge of the panty on only its "inner"surface or both its "inner" and "outer" surfaces so long as a portion ofthe flap extends around and about the edge of the panty.

The sanitary napkin of this invention has been described as a devicewhich has two flaps which, in use, each form a wall. While thoseembodiments are highly preferred, devices not having flaps or havingonly one flap can be envisioned. This one flap would be associated withthe central absorbent means along a nonlinear line of juncture. The flapwould contain at least two, and preferably at least four, axes offlexibility which would allow it to form both walls described above asit is folded completely around the crotch portion of a panty. The flapwould then be associated with the central absorbent means along anonlinear line of juncture opposite the one mentioned above.

In the embodiments of the sanitary napkin of this invention, illustratedand discussed above, adhesive attachment means were present near thedistal edges of the flaps and in register with the central absorbentpad. These elements, designed to hold the sanitary napkin securely inthe crotch region of an undergarment, are highly preferred elements.Without detracting from that position, it can be asserted thatembodiments of the present invention which effectively lack one or moreof the described adhesive attachment means are also useful, novel,effective devices.

The embodiment illustrated in FIGS. 1 and 2 can be readily adapted tofunction as an embodiment of the present invention which is effectivelyfree of one or more of the adhesive attachment means.

For example, central pad adhesive 220 (and, naturally, its associatedcentral pad release liner 222) can be omitted from sanitary napkin 210illustrated in FIGS. 1 and 2. In use, this modified embodiment would beplaced in the interior crotch region of a panty, just as the unmodifiedembodiment, except that central absorbent pad 220 is not secured to theinterior crotch region of the panty. Flaps 224 and 224' can be securedabout the elastic edge of the panty as described above with flapadhesive 236 and 236'. The panty with its associated modified sanitarynapkin would then be donned by the user as before. Flap adhesive 236 and236' in cooperation with the elastic edges of the panty hold themodified sanitary napkin in place.

In a like manner, sanitary napkin 210 can be modified by omitting onlyflap adhesive 236 and 236' (and release liners 238 and 238'). Themodified sanitary napkin would be secured in the crotch region of thepanty with central pad adhesive 220 and the flaps would be merely foldedabout the elastic edges.

In a like manner, sanitary napkin 210 can be modified by omitting allflap and central pad adhesives. In use, such a modified sanitary napkinwould be maintained in position solely by cooperation among the flaps,the elastic edges of the panty, and the user's body.

FIG. 3 shows an embodiment wherein the topsheet 40 comprises a centralpad 105 and is folded over at its marginal parts 103. At the perimeterof the core 48 the topsheet comprises two layers that are bondedtogether for instance by adhesive or ultrasonic fusion bonding. The freeedge 109 of the wall 107 that is formed by the topsheet, is located ontop of the absorbent core 48 within its perimeter that is defined bysides 226 and 226' as shown in FIG. 1. To the free edge 109 acontraction member is connected in the form of an elastic 77.

In the embodiment of FIG. 4, the walls 107 are formed by the backsheet42 that is wrapped around the core 48 and that is connected to thetopsheet 40 in bond areas 108 at the top of the core.

In the embodiment as shown in FIG. 5, the wall 107 is formed by a foamstrip 100 which is located underneath the topsheet on top of the core48. The sanitary napkin of FIG. 5 is provided with wings 43 forconnection to a user's garment as shown in FIG. 10.

In the embodiment of FIG. 6, the wall 107 is formed by a flexiblecantilever 102 which is connected between the topsheet 40 and thebacksheet 42.

FIG. 7 is a fragmentary sectional view and depicts the construction inthe crotch region of a further embodiment of a sanitary napkin accordingto the invention as it is shaped before being applied to the wearer(i.e. the napkin is subjected to elastic contraction). The absorbentcore 44 comprises the absorbent layer 48 that is shown as beingcompletely enveloped by the first and second tissue layers 50 and 52.The absorbent core 44 is disposed between the topsheet 38 and thebacksheet 42, both the topsheet 38 and the backsheet 42 extend beyondthe side edge 46 of the absorbent core 44 to define the side flap 58.The juxtaposed areas of the topsheet 38 and the backsheet 42 areadhesively secured together by adhesive 88.

The barrier means 62 is shown as being formed by securing an element tothe topsheet 38 between the flap's outer edge and the side edge 46 ofthe absorbent core 44. The proximal edge 64 of the barrier means 62 isformed by securing the barrier means element to the topsheet 38 byadhesive 92. The spacing elastic members 77 are enclosed in a tunnelthat is formed when an end of the barrier means element is folded backupon itself; the spacing elastic members 77 being secured in the barriermeans 62 by elastic attachments means 94. The distal edge 66 of thebarrier means is spaced away from the topsheet top surface 40 by theelastic gathering action of the spacing elastic members 77; a channel 96thereby being formed by at least the proximal edge 64, the distal edge66 and the inboard surface 68 of the barrier means 62. The channel 96 isshown as being ready to restrain, contain and hold body fluids until thesanitary napkin 210 is removed from the wearer.

The topsheet 38 is compliant, soft feeling, and non-irritating to thewearer's skin. Further, the topsheet 38 is liquid pervious permittingliquids to readily penetrate through its thickness. A suitable topsheetmay be manufactured from a wide range of materials, such as porousfoams, reticulated foams, apertured plastic films, natural fibers (e.g.wood or cotton fibers), synthetic fibers (e.g. polyester orpolypropylene fibers) or from a combination of natural and syntheticfibers. Preferably, it is made of a hydrophobic material to isolate thewearer's skin from liquid in the absorbent core 44.

A particularly preferred topsheet 38 comprises staple lengthpolypropylene fibers having a denier of about 1.5, such as Hercules Type151 polypropylene marketed by Hercules Inc. of Wilmington. Del. As usedherein, the term "staple length fibers" refers to those fibers having alength of at least about 15.9 mm (0.625 inches).

There are a number of manufacturing techniques which may be used tomanufacture the topsheet 38. For example, the topsheet 38 may be woven,non-woven, spunbonded, carded, or the like. A useful topsheet 38 iscarded, and thermally bonded by means well known to those skilled in thefabrics art. Preferably, the topsheet 38 has a weight from about 18 toabout 25 grams per square meter, a minimum dry tensile strength of atleast about 400 grams per centimeter in the machine direction and a wettensile strength of at least about 55 grams per centimeter in the crossmachine direction.

The absorbent core 44 may be any means which is generally compressible,conformable, non-irritating to the wearer's skin, capable of absorbingand retaining body fluids. A preferred absorbent core 44 has first andsecond opposed faces and comprises an absorbent layer 48 and first andsecond tissue layers 50 and 52, respectively. The first and secondtissue layers 50 and 52 overlay the major surfaces of the absorbentlayer 48 to form the first and second opposed faces of the absorbentcore.

The absorbent layer 48 may be manufactured in a wide variety of sizesand shapes (e.g. rectangular, hour-glass, etc.) and from a wide varietyof liquid absorbent materials commonly used in absorbent articles, suchas comminuted wood pulp which is generally referred to as airfelt.Examples of other suitable absorbent materials include creped cellulosewadding, absorbent foams, absorbent sponges, super absorbent polymers,or any equivalent material or combination of materials. The totalabsorbent capacity of the absorbent layer 84 should, however, becompatible with the design body fluid loading in the intended use of thesanitary napkin. Further, the size and absorbent capacity of theabsorbent layer 48 may be varied to accommodate wearers.

The dimensions, shape, and configuration of the absorbent layer 48 maybe varied (e.g. the absorbent layer may have a varying caliper, or ahydrophillic gradient, or may contain superabsorbent materials orsynthetic fibers.

The first and second tissue layers 50 and 52 improve the tensilestrength of the absorbent core 44 and reduce the tendency of theabsorbent layer 48 to split, lump or ball when wetted. The first andsecond tissue layers 50 and 52 also help to improve lateral wicking ofthe absorbed body fluids thereby providing a more even distribution ofthe body fluids throughout the absorbent layer 48. While a number ofmaterials and manufacturing techniques may be used to manufacture thefirst and second tissue layers 50 and 52, satisfactory results have beenobtained with sheets of tissue paper having a basis weight of about 16grams per square meter (10 lbs. per 3000 square fee) and having an airpermeability of about 30.5 cubic meters per minute per square meter (100cubic feet per minute per square foot) at a pressure differential ofabout 12.8 millimeters of water (0.5 inch). While the first and secondtissue layers 50 and 52 are preferably coterminous with the absorbentlayer 48, they may have different dimensions, a different configuration,or they may be omitted entirely.

The absorbent core 44 is superimposed on the backsheet 42 and ispreferably attached thereto by attachments means (not shown) such asthose well known in the art. For example, the absorbent core 44 may besecured to the backsheet 42 by a uniform continuous layer of adhesive, apatterned layer of adhesive, or an array of separate lines or spots ofadhesive. An adhesive which has been found to be satisfactory ismanufactured by Eastman Chemical Products Company of Kingsport, Tenn.and marketed under the tradename Eastobond A-3.

The backsheet 42 is impervious to liquids and is preferably manufacturedfrom a thin plastic film, although other flexible liquid imperviousmaterials may also be used. The backsheet 42 prevents the body fluidabsorbed and contained in the absorbent core 44 from wetting articleswhich contact the sanitary napkin such as undergarments. Preferably, thebacksheet 42 is a polyethylene film having a thickness of from about0.012 mm (0.5 mil) to about 0.051 cm (2.0 mils), although otherflexible, liquid impervious materials may be used. As used herein, theterm "flexible" refers to materials which are compliant and which willreadily conform to the general shape and contours of the human body.

A suitable polyethylene film is manufactured by Monsanto ChemicalCorporation and marketed in the trade as Film No. 8020. The backsheet 42can be embossed and/or matte finished to provide a more clothlikeappearance. Further, the backsheet 42 may permit vapors to escape fromthe absorbent core 44 while still preventing body fluid from passingthrough the backsheet 42.

The topsheet 38 and the backsheet 42 are associated together in anysuitable manner. As used herein, the term "associated" encompassesconfigurations whereby the topsheet 38 is directly joined to thebacksheet 43 by affixing the topsheet 38 directly to the backsheet 42,and configurations whereby the topsheet 38 is indirectly joined to thebacksheet 42 by affixing the topsheet 38 to intermediate members whichin turn are affixed to the backsheet 42. In a preferred embodiment, thetopsheet 38 and the backsheet 42 are joined directly to each other inthe periphery by attachment means such as adhesive 88 or any otherattachment means as known in the art. For example, a uniform continuouslayer of adhesive, a patterned layer of adhesive, or any array ofseparate lines or spots of adhesive may be used. The side flap 58 shouldbe highly flexible.

The side flaps 58 are that portion of the sanitary napkin between theperiphery and the edges of the absorbent core 44. Thus in an embodimentof the present invention as shown in FIG. 7, the side flaps 58 areformed from the extension of the backsheet 42 and the topsheet 38 fromand along the side edges 46 of the absorbent core 44.

Each barrier means 62 is a flexible member having a proximal edge 64, adistal edge 66, an inboard surface 68 and an outboard surface 70. Asused herein, the term flexible refers to materials which are compliantand will readily conform to the general shape and contours of the body.In addition, if the spacing means 76 comprise spacing elastic members77, the barrier means 62 must be contractible so that the distal edge 66may be sufficiently spaced away from the topsheet top surface 40 so thata channel 96 is formed to restrain, contain and hold body fluids withinthe article. The barrier means 62 may be manufactured from a widevariety of materials such as, polyester, rayon, nylon, foams, plasticfilms, formed films, and elastic foams. A number of manufacturingtechniques may be used to manufacture the barrier means. For example,the barrier means 62 may be woven, non-woven, carded, or the like. Aparticularly preferred barrier means 62 comprises a material containingno finish or to render it liquid impermeable. A particularly preferredmaterial is manufactured by Crown Zellerbach Company as Celestra.

As shown in FIG. 7, the barrier means 62, and more particularly theproximal edge 64, is disposed inboard of and preferably adjacent to theflap.

The term "inboard" is defined as the direction toward the center line 36that is parallel to the respective edge (226, 226') along which theparticular barrier means 62 is disposed.

The barrier means 62 is disposed to provide a more effective restraintagainst the flow of body fluids. The barrier means 62 is preferablydisposed between the flap's outer edge and the longitudinal center line36 of the sanitary napkin.

The proximal edge 64 and the distal edge 66 are in spaced relation toeach other and define the width of the barrier means 62. The proximaland distal edges 64 and 66 respectively, may be in a parallel, nonparallel, rectilinear or relationship. In addition, the barrier means 62may have a variety of different cross sectional areas includingcircular, square, rectangular or any other shape. Preferably, theproximal edge 64 is spaced from the distal edge 66 in a parallel andrectilinear relationship to provide a barrier means 62 having uniformwidths.

The embodiment of the sanitary napkin shown in FIG. 7 is provided withthe barrier means 62 joined to the topsheet 38. The term "joined"includes any means for affixing the barrier means 32 to the sanitarynapkin and includes embodiments wherein the barrier means 62 is aseparate element having the proximal edge 64 directly or indirectlyattached to the topsheet 38 (i.e. integral) or embodiments wherein thebarrier means 62 is made from the same element or material as thetopsheet 38 so that the proximal edge 64 is a continuous and undividedelement of the topsheet (i.e. unitary). The barrier means 62 mayalternatively be joined to the side flap 58, the backsheet 42, theabsorbent core 44, the topsheet 38 or any combination of these or otherelements of the sanitary napkin. In the embodiment as shown in FIG. 2,the barrier means 62 are integral with the topsheet 38. The integralbarrier means 62 is preferably formed by a single strip of materialwhich is secured to the topsheet by adhesive 92, the distal edge 66being formed by folding an end of the material back upon itself.

The distal edge 66 is preferably disposed inboard of the proximal edge64 a present a more effective barrier against the flow of. The distaledges 66 are maintained inboard of the proximal edges 64 by the adhesivemeans 78 so as to obviate their inversion. While the distal edges 66 mayalternatively be disposed in other positions in relation to the proximaledges 64, such positions are not preferred.

The distal edge 66 is preferably not secured to any other element in atleast a centre region of the sanitary napkin so that it may be spacedaway from the top surface 40 of the topsheet 38. The distal edge 66 ispreferably spaced away from the top surface 40 of the topsheet 38 sothat the barrier means 62 may form a channel 96 to enhance thecontainment of the article. As used herein, "spaced" includes embodimentwherein the distal edges 66 may assume one or more positions relative tothe top surface 40 of the topsheet 38 including at some times assuming aposition adjacent the top surface 40 of the topsheet 38. The distancebetween the distal edge 66 to the top surface 40 of the topsheet 38 ismeasured along a line drawn from the distal edge 66 to the closest partof the topsheet 38 when the distal edge 66 is positioned so as to bespaced away from the topsheet as far as possible, (i.e. in thecontracted position). Preferably, the distal edge 66 is spaced away fromthe topsheet 38 by a height of at least about 2 mm, and more preferablyof from about 5 mm to about 10 mm.

The channel 96 is formed at least along the proximal and distal edges 64and 66 and the inboard surface 68 of the barrier means 62. The channel96 forms a barrier to the flow of bodyfluid as they tend to move acrossthe topsheet 38.

The barrier means 62 may additionally be provided with absorbent meanssecured to or within the barrier means 62. The absorbent means absorband contain body fluid which contact the barrier means 62. The absorbentmeans may be any means which is capable of absorbing and retainingliquid and may have any size, shape, configuration or absorbentcapacity. The absorbent means may be positioned to the barrier means 62along the inboard surface 68 or within the barrier means 62. Preferably,the absorbent means is a layer of airfelt secured within the tunnelformed by the integral barrier means and secured along the entire lengthand width of the inboard surface 68 of the barrier means 62.

In addition, the barrier means 62 may be rendered liquid impermeable soas to prevent the of bodyfluid. A liquid impermeable barrier means 62retards the movement of liquid through the barrier means 62, therebymaking it more leakage resistant. The barrier means 62 may be renderedliquid impermeable in any manner well known in the art such asselectively treating the barrier means, the barrier means, or bysecuring a separate material to the barrier means.

The spacing means 76 for spacing the distal edge 66 away from thetopsheet top surface 40 is any member which gathers, contracts,stiffens, shortens or otherwise acts on the barrier means 62 so as tocause a channel 96 to be formed along the barrier means 62 to provide aconstraint against the leakage of.

As shown in FIG. 7 the spacing means 76 preferably comprise spacingelastic member 77 secured adjacent the distal edge 66 inside of thebarrier means 62. The spacing elastic member 77 is preferably secured tothe barrier means 62 in an contractible condition so that in a normallyunrestrained configuration, the spacing elastic member 77 effectivelycontracts or gathers the barrier means 62.

As shown in FIG. 7, the spacing elastic member 77 is associated with thebarrier means 62 by securing it within the barrier means with elasticattachment means 94. While the spacing elastic members 77 may be securedto the barrier adjacent only the ends of the elastic spacing member 77,it is preferable to secure the entire length of the spacing elasticmember 77 to the barrier means 62. The elastic attachment means 94herein are preferably glue beads made of hot melt adhesive such asmarketed by Adhesives Incorporated, Wis., as Adhesives 581.

A spacing elastic member 77 which could be suitable is an elastic strandhaving a cross section of 0.18 mm by 1.5 mm and made from natural rubberas available from Rubber Company of, Va., under the trademark L-1900Rubber Compound. Other suitable spacing elastic members 77 can be madefrom natural rubber, such as elastic tape sold under the trademark 9211by Company of Scotland. N.C. The spacing elastic member 77 may alsocomprise any heat shrinkable elastic material as is well known in theart. Other suitable elastic materials may comprise a wide variety ofmaterials as are well known int he art include films, polyurethanefilms, foams and formed elastic.

In addition, the spacing elastic members 77 may take a multitude ofconfigurations. For example, the width of the spacing elastic members 77may be varied; the spacing elastic members may comprise a single strandor several parallel or non-parallel strands of elastic material; or thespacing elastic members 77 may be rectilinear or curvilinear. Stillfurther, the spacing elastic members 77 may be affixed to the barriermeans 62 in any of several ways which are well known in the art. Forexample, the spacing elastic members 77 may be bonded or heat sealedinto the barrier means 62 using a variety of bonding patterns, or thespacing elastic members 77 may simply be glued to the barrier means 62.

The spacing means 76 for spacing the distal edge 66 away from thetopsheet top surface 40 may alternatively comprise several otherelements. For example, the barrier means 62 may have stiffening meansdisposed in or on each barrier means 62. The stiffening means must besufficiently stiff so that the distal edge 66 is spaced away from thetopsheet top surface 40. Suitable materials for the stiffening meansinclude foams, fabrics, batting, polyethylene film formed films, sprayglues, foamed polyester, or a high loft material as is manufactured byCarolina Formed Fabrics.

The spacing means 77 may also comprise means for shortening the lengthof the distal edge 66 in comparison to the length of the edges of thesanitary napkin. The distal edge 66 can be shortened by making a fold orpleat in the distal edge 66. This fold or pleat is secured by any of theholding means well known to those of ordinary skill in the art, such asadhesives or heat sealing. Alternatively, a section may be cut out ofthe distal edge and the edges brought together to form a butt or joint.The distal edge 66 may also be shortened by attaching a length of thedistal edge 66 to the topsheet 38 at a position different from where thedistal edge 66 would lie when the sanitary napkin is in a flattened outcondition. Other shortening techniques as are known in the art may alsobe used.

The adhesive means for securing end portions of the barrier means 62closed near the lateral edges of the sanitary napkin provide a morecomfortable fit for the wearer and obviate inversion of the distal edges66 of the barrier means 62 during application and use. Inversion isgenerally defined as the inboard disposed distal edge 66 turningoutwardly when the sanitary napkin is applied to the wearer. In apreferred embodiment such adhesive means are disposed in the frontregion and the back region of the sanitary napkin. The remainingportions of the barrier means 62 are not secured closed so that thedistal edges 66 are left freely.

The adhesive means 78 are preferably glue beads 79 consisting of hotmelt adhesives such as marketed by Adhesives Incorporated, Wis., asAdhesives 581.

We claim:
 1. A sanitary napkin of the type for placement in anundergarment, the sanitary napkin comprising:(a) a central absorbent padhaving a pair of longitudinal edges, a body contacting surface, acentral region, and a pair of ends, said central absorbent padcomprising:a liquid pervious topsheet; a liquid impervious backsheetjoined with said topsheet; and an absorbent core positioned between saidtopsheet and said backsheet; (b) a flap extending outwardly from eachlongitudinal edge of said central absorbent pad in said central region,each said flap being joined with said central absorbent pad and beingsized and configured to allow each of said flaps to be positioned aroundthe edge of an undergarment at a flexible axis so as to form a wall, inuse; and (c) barrier means for restricting liquid migration in thegeneral direction of the lateral sides, each said barrier meanscomprising:(i) a barrier element havinga proximal edge joined to saidflap, and a free edge spaced from said proximal edge and being free fromsecurement to at least a portion of said flap and said central absorbentpad; and (ii) spacing means joined adjacent said free edge for spacingsaid free edge upwardly about said proximal edge and away from said bodycontacting surface of said central absorbent pad so as to form a secondwall providing a barrier to the lateral flow of body fluids, in use. 2.The sanitary napkin of claim 1 wherein said spacing means comprises aspacing elastic member secured to said barrier element in an elasticallycontractible condition to gather or contract said barrier elementadjacent said free edge.
 3. The sanitary napkin of claim 2 wherein eachsaid barrier element is liquid impermeable.
 4. The sanitary napkin ofclaim 3 additionally comprising a central pad adhesive means positionedon said backsheet and a flap adhesive means positioned on each of saidflaps for securing the sanitary napkin to a wearer's undergarment. 5.The sanitary napkin of claim 4 wherein said free edges of said barrierelement are maintained inboard of said proximal edge by an adhesivemeans for obviating inversion of said barrier elements.
 6. The sanitarynapkin of claim 5 wherein said topsheet of said central absorbent padextends to said flaps and forms a portion of a topsheet for said flaps.7. The sanitary napkin of claim 2 additionally comprising a central padadhesive means positioned on said backsheet and a flap adhesive meanspositioned on each of said flaps for securing the sanitary napkin to awearer's undergarment.
 8. The sanitary napkin of claim 2 wherein saidtopsheet of said central absorbent pad extends to said flaps and forms aportion of a topsheet for said flaps.
 9. The sanitary napkin of claim 1wherein each said barrier element is liquid impermeable.
 10. Thesanitary napkin of claim 9 additionally comprising a central padadhesive means positioned on said backsheet and a flap adhesive meanspositioned on each of said flaps for securing the sanitary napkin to awearer's undergarment.
 11. The sanitary napkin of claim 9 wherein saidtopsheet of said central absorbent pad extends to said flaps and forms aportion of a topsheet for said flaps.
 12. The sanitary napkin of claim 1additionally comprising a central pad adhesive means positioned on saidbacksheet and a flap adhesive means positioned on each of said flaps forsecuring the sanitary napkin to a wearer's undergarment.
 13. Thesanitary napkin of claim 12 wherein said spacing means comprises aspacing elastic member secured to said barrier element in an elasticallycontractible condition to gather or contract said barrier elementadjacent said free edge.
 14. The sanitary napkin of claim 12 whereinsaid topsheet of said central absorbent pad extends to said flaps andforms a portion of a topsheet for said flaps.
 15. The sanitary napkin ofclaim 1 wherein said flaps additionally comprise a second axis offlexibility within the flap so that the flap is extremely flexible overessentially the whole of its extent.
 16. The sanitary napkin of claim 1wherein said flaps are formed independently from said central absorbentpad and joined to said central absorbent pad.
 17. The sanitary napkin ofclaim 1 wherein said topsheet of said central absorbent pad extends tosaid flaps and forms a portion of a topsheet for said flaps.
 18. Thesanitary napkin of claim 1 wherein said free edges of said barrierelement are maintained inboard of said proximal edge by an adhesivemeans for obviating inversion of said barrier elements.